The present invention is directed to an adapter for coupling a patient breathing circuit to a ventilator. In the preferred embodiment, the present invention relates to a breathing circuit adapter for interconnecting a patient's breathing circuit, a pressure monitor, a source of aerosolized medicine and a ventilator.
Patients that have ventilatory difficulties are often placed on a ventilator. A ventilator is a mechanical device designed to provide all or part of the work a body must produce to move gas into and out of the lungs. The ventilator delivers breathable gas to a patient and carries breathed gas from the patient through a set of flexible tubes called a patient breathing circuit. Typically, the patient breathing circuit connects the ventilator to an endotracheal or tracheostomy tube that extends into the patient's throat or to a mask covering the patient's mouth and/or nose. Such a connection is often made via a Y-piece connector, which unites the inhalation and exhalation conduits and provides a means for permitting gas flow in either conduit based upon whether patient inhalation or exhalation is occurring. The endotracheal tube or tracheotomy tube may include a balloon cuff to provide a seal inside the trachea for the tracheal tubes or a mask may have a seal around the mouth and nose to sustain a predetermined air pressure within the circuit and patient lungs.
Most ventilators have at least one pressure monitor that measures patient airway pressures to gauge the pressure of the breathing gas delivery and whether or not the patient is properly connected to the ventilator. Many ventilators have sophisticated pressure, volume and flow sensors that produce signals both to control the ventilator output and to provide displays of how the ventilator and patient are interacting.
To medicate a patient on a ventilator, aerosolized medicine is often installed into the breathing circuit. A device for delivering aerosolized medicine, such as a nebulizer, introduces the aerosoled medication periodically as prescribed into the breathable gas flowing through the inspiratory conduit of the patient circuit and ultimately to the patient's airway and lungs. As with any dispensation of medication to a patient, it is desirable to provide a delivery device/ventilator/breathing circuit adapter that optimizes dosage control and maximizes deposition of aerosolized medicine in the inhaled gas.
Typically, devices for delivering aerosolized medicine, such as nebulizers, have been coupled to the patient circuit proximate to the patient interface (i.e. the endotracheal or tracheostomy tube or mask) at the Y-piece connector. However, recent studies have concluded that in many instances coupling the nebulizing device to the patient circuit proximate to the ventilator provides better deposition of aerosolized medicine during the inhalation phase. During the exhalation phase the ventilator, or nebulizer, provides a small bias flow rate while the nebulizing device continuously atomizes medicine at a fixed rate. With the nebulizer placed proximate to the ventilator (at the distal end of the inspiratory circuit relative to the patient), the bias flow charges the inspiratory circuit with aerosol during the expiratory phase. In contrast, aerosol generated with the nebulizer positioned at the patient Y-piece is directed down the expiratory conduit of the patient circuit during the exhalation phase, reducing the amount of medicine available to the patient.
For the foregoing reasons, an efficient means for coupling a patient breathing circuit to a ventilator is desirable. An efficient means for coupling a delivery device for aerosolized medicine to a patient breathing circuit proximate to a ventilator is also greatly desired. Specifically, it is desirable to provide a breathing circuit adapter for interconnecting a delivery device for aersolized medicine, such as a nebulizer, proximate to a ventilator and distal from the patient relative to the inspiratory circuit, thus maximizing efficiency and the amount of medicine provided to the patient. It is desirable to provide such a breathing circuit adapter which is simple, easy to use, and comprises minimal parts to therefore minimize chances for mechanical breakdown.